US President Donald Trump has told the group of migrants trying to reach the United States to “turn around” and “go back” to their country.
Mr Trump said the country was not letting people in illegally, after he ordered hundreds of troops to go to the Mexico border to intercept Migrants.
The President has previously described the caravan of thousands of central American people heading for the US as a "national emergency".
On Thursday, Mr Trump tweeted directly to those who were trying to make the 1,000 mile journey to the US.
He said: “To those in the Caravan, turn around, we are not letting people into the United States illegally.
“Go back to your Country and if you want, apply for citizenship like millions of others are doing!”
Defence Secretary Jim Mattis has confirmed he is set to sign an order sending at least 800 troops to the US-Mexico border, officials said.
The additional troops are to provide what one official described as logistical support to the Border Patrol.
Some 2,000 National Guard servicemen are already assisting at the border after an earlier order, as the group travelled through Mexico.
The group of migrants formed a mile long column as they trekked out of the town of Mapastepec this morning, having spent the nights in portable tents and plastic sheets.
Volunteers and local churches offered support, including medicines, baby bottles, clothing and shower facilities.
The group had walked around 95 miles when they crossed the border into Mexico on October 19, as they make the 1,000 mile journey to the US.
There are reports the numbers are reducing as sickness, fear and police harassment drive some to disband from the larger group
